Zaha returned to the Palace team following a knee injury as they beat Huddersfield on Saturday, with Townsend keen to underline the importance of the Ivorian to the 'Eagles'.
"Yeah I think that's a massive boost," Townsend said when asked about Zaha's return.
"The stats when he's not in the team - I don't need to harp on about it, but he's an incredible player for us.
"We need to keep him fit if we're going to survive and get more performances from him like he did today and drag us to more victories."
Despite the talent in the Palace squad, Townsend believes that guts and determination will play just a much of a rol in keeping the club afloat.
"In a relegation battle you need more than talent. You need heart and desire," he explained.
"You need everything we showed out there today and we're going to need that same attitude in the last seven games if we're going to survive.
"I've been in teams before when people said we were too good to go down, we know that's never the case.
"We've had a lot of injuries to key players at key moments. Hopefully everyone's on the way back and we can have a strong end to the season and finish on a high.